Method and apparatus for preparing coffee drinks

ABSTRACT

The invention relates to a method for making coffee-based drinks and to an arrangement in an apparatus for making coffee-based drinks. In this process, coffee is made by means of a so-called expresso method using hot water. High pressure and a short boiling time. According to the method, a strong coffee concentrate is stored in a hermetically sealed heat vessel and the concentrate is either used as such or it is diluted so as to obtain a desired strength at the moment of serving by adding a suitable amount of water to the concentrate in a mixing tank. According to the invention, both expresso-based specialty coffees and ordinary coffee are made by means of the same equipment. The invention also makes it possible to quickly serve large amounts of coffee.

The present invention relates to the preparation of coffee drinks, andparticularly to the method according to the preamble of Claim 1 formaking coffee-based drinks.

According to such a method, coffee is made by means of a so-calledespresso method using hot water, high pressure and a short boiling time,from fine coffee powder that is ground up from dark roasted coffeebeans. Very strong coffee is thus obtained, which can be called aconcentrate because of its small amount of water and high content ofcoffee.

The invention also relates to the arrangement according to the preambleof Claim 9 for making coffee drinks.

A good taste and the easiness of preparation constitute the basis forthe commercial use of coffee. The most difficult task is to make andpreserve large amounts of good coffee. In the Nordic Countries, the mostfamiliar way to make coffee is by boiling or filtering so as to make adrink that is easy to enjoy even in larger amounts at a time. Incontrast, generally stronger coffee of the espresso type is consumed inthe Mediterranean.

For large-scale consumption, coffee is made into a container or separatecontainers that are used to serve the coffee. The coffee is made eitherby manual or automatic percolators. Such coffee makers require a lot ofspace and it is difficult to maintain the quality of the coffee. Thesepercolators are only made to serve so-called filtered coffee.

In the industry, coffee is also made into a concentrate that is packedand frozen in disposable packages (bib), and thawed and placed intospecial distribution devices before use, wherein some concentrate ismixed with hot water and served as coffee. Coffee is also made of aninstant powder, i.e., instant coffee powder, by mixing it with hotwater. Instant coffee powder is manufactured industrially by removingwater from filtered coffee.

Publication WO A1 01/74211 discloses a solution for making coffee. Thecoffee is made by mixing water and coffee concentrate that is made inadvance by another device. Espresso is also made merely by means oftreating with steam, coffee that is stored in advance.

Publications WO A1 02/01993, U.S. Pat. No. 4,470,999 and U.S. Pat. No.3,641,918 also disclose a solution, wherein a coffee drink is made of aprefabricated product. The product that is made into a drink can befreeze-dried, ordinary instant coffee powder or a liquid concentrate,which either has been stored or is stored in a cold place or is frozen.The concentrate can also be prepared in advance by another device eitherby filtering or boiling.

The known technology involves considerable drawbacks. In industrialprocesses, coffee is first made and then cooled after the process, untilheated again in dispensers. Thus, the coffee concentrate is prepared andserved by means of separate devices. Heating ready-made coffee is thesurest way to spoil its taste and aroma, and reheated coffee cannotcompete with the aromas of freshly-made coffee.

At the moment, separate coffee makers are needed to make so-calledordinary coffee and espresso-based types of coffee, which are alsocalled specialty coffees. On the market, there are some combined coffeemakers, which can be used to make both filtered coffee and espresso but,in practice, these devices are combinations of two coffee makersintended for small-scale use, combining two cookers within one case. Thegreatest disadvantage of also these cookers is that they can only makeone cup of espresso-based coffee at a time.

Espresso-based coffees and the specialty coffees that are made on thebasis of espresso coffee are made at the moment they are served; theycannot be preserved, and the larger the amounts of specialty coffee thatare to be made at one time, the more effective and expensivemanufacturing devices are needed

At present, when large amounts of both ordinary coffee and specialtycoffee are made, at least two different coffee makers are needed andmore space should be reserved for them; besides, also the investmentcosts are higher. By means of current devices, only one cup of specialtycoffee can be made at a time, therefore, to make large volumes, severalcookers are needed, the manufacture is time-consuming, thus slowing downthe process of serving specialty coffee.

The purpose of the present invention is to eliminate the disadvantagesof the known technology and to provide a new solution for thepreparation of coffee drinks.

The invention is based on the idea that different types of coffee, boththose based on espresso and the ordinary, so-called percolated coffee,are made by means of one device.

The invention is further characterized in that a strong coffeeconcentrate is stored in a hermetically sealed heat vessel, and theconcentrate is either used as such or diluted at the moment of servingso as to form a desired concentrate by adding a suitable amount of waterinto the concentrate in a mixing tank.

To be more precise, the method according to the invention ischaracterized in that, which is presented in the characterizing part ofClaim 1.

The arrangement according to the invention, in turn, is characterized inthat, which is presented in the characterizing part of Claim 9.

The invention provides considerable advantages. By using the solutionaccording to the invention, a large amount of coffee can be made andpreserved in a high-quality concentrated form by means of simpleequipment. No such device is previously known, which in advance makesand also stores fresh coffee in concentrated form and uses thisconcentrate to make both ordinary and specialty coffees. The solutionpresented herein makes it possible to quickly make and serve largeamounts of espresso-based coffees. The price and size of such a deviceare clearly smaller than those of the present solutions that offer acorrespondent capacity. The new solution also offers a higher speed ofmanufacture and service than the known apparatuses. This problem hasearlier been solved for ordinary filtered coffee only.

By means of our invention, both ordinary coffee and specialty coffeescan be made using the same device. The space needed by the new equipmentis clearly smaller than the space needed by the corresponding, currentcoffee makers together. The price and the energy demand are distinctlylower compared with the two earlier devices that have a correspondingcapacity. The new solution also offers a higher manufacturing andserving speed of specialty coffees. This is of importance in thecatering business and institutional catering in particular, where largevolumes of coffee are to be served quickly.

The invention can also be used in making tea and other hot drinks.

The short manufacturing time, the high pressure and the correct roastingof the espresso method also provide an advantage, which has not beengiven attention earlier. Because of the quick preparation, the coffeedrink seals in the fresh taste and the aromas of coffee, but theundesirable ingredients of coffee bean, such as acids and wastematerials, which dissolve as a consequence of a long extraction time,are omitted. Hence, the “ordinary” coffee made in accordance with theinvention is more delicious than the conventional filtered coffee thatis made by the traditional slow method of extraction, because thefinished drink lacks the undesirable flavourings of the coffee bean.

The coffee maker solutions that are presently used commercially arebased on processing and serving prefabricated coffee concentrates. Nopublication discloses a solution, wherein ordinary coffee and specialtycoffees can be made, preserved and served by the same equipment, andwhere the ready-made coffee base can also be used for so-called coffeedrinks.

Recently made coffee tastes better and fresher than that made of aconcentrate or powder.

In the following, the invention is studied in detail with the aid of theappended drawing.

FIG. 1 is a schematic drawing of the coffee making arrangement accordingto the invention, which can be used to make both ordinary coffee andspecialty coffee.

Even though the following mainly describes the making of coffees andcoffee drinks, it is obvious that the invention can also be applied tomaking tea and corresponding stimulant drinks, whereby, instead ofcoffee made by the espresso method, first, a corresponding teeconcentrate is produced.

The following numerals are used in the figure:

-   -   1 a Hot-water tank    -   1 Hot-water pipe    -   2 Valve    -   3 Control valve    -   4 Cold-water pipe    -   5 Valve    -   6 Control valve    -   7 Mixing tank    -   8 Control valve    -   9 Valve    -   10 Pipe from hermetic vessel to the mixer    -   11 Hermetically closed heat vessel    -   12 Pipe for fresh coffee concentrate/tea    -   13 Outlet pipe with air lock    -   14 Sensing elements for controlling the hermetic vessel    -   15 Serving dish    -   16 Pressure cooker for coffee/tea    -   17 Dosing valve    -   18 Pressure tank for hot water    -   19 Water pump

According to our invention, coffee is made in the pressure cooker 16 bymeans of the espresso method. Water is introduced into the heatedpressure tank by means of the pump 18. Hot water from the pressure tank18 is measured into the cooker 16. The amount of water is controlledusing the valve 17. The prepared coffee concentrate travels along thepipe 12 into the hermetically sealed heat vessel 11. The coffee remainsin the vessel for a selected dwell time. The dwell time can be selectedin advance or, alternatively, it is determined in accordance withconsumption. In the storage vessel, coffee concentrate is present in anamount of at least 2% of the volume of the vessel all the time, servingas a buffer. Air exits from the heat vessel along the pipe 13 and givesway to the concentrate. The drink is selected by means of an optionbutton, whereby the valve 9 opens and lets some concentrate through thevalve 8 along the pipe 10 to the dispenser/mixer 7 and through there tothe serving dish 15.

The “espresso method” herein refers to a manufacturing method, whereinthe concentrate is extracted from a coffee powder that is in acompressed state, by compressing water at about 90 to 92° C. through itat a pressure of 6 to 10 bar in a very short time. Generally, the amountof coffee is very small, 7 to 15 g, preferably 8 to 12 g, e.g. about 10g and, correspondingly, the amount of water only about 5 cm³. Themanufacturing time of the small amount is about 15 to 20 seconds, andmaking an amount twice as large should also take place within a shortperiod of time (about 36 seconds).

Tea can also be made by the pressure cooker 16.

The hermetic vessel herein refers to an essentially closed, airtightvessel, wherein, when the coffee concentrate rises to the vessel, acorresponding amount of air exits the vessel, for example, through anoutlet pipe provided with an air lock, or a similar valve system.Correspondingly, the amount of the air flowing into the vessel throughthe air lock or the like is no larger than the amount of liquid exitingthe vessel. The vessel is isolated from the ambient air, so that itscontents remain unchanged. The amount of the extra air entering thevessel is exactly the same as the amount of liquid removed, leakage fromthe vessel being insignificant. The vessel is isolated, so that it ispossible to keep the coffee concentrate at a temperature selected inadvance. The vessel can also be heatable. The hermetic aspect of theheat vessel makes it possible to keep the coffee concentrate fresh andflavoured.

According to an advantageous embodiment, the temperature in the storagevessel can be within a range of 85 to 92° C., preferably 90 to 92° C.

The air lock can be, for example, a pipe that is bent so as to form asemi-arch, which has a downward mouth opening.

According to the drink selected and to ensure the correct taste nuanceand temperature, hot water can be added to the concentrate from thehot-water storage tank 1 a along the pipe 1 by means of the valve 2, inan amount controlled by the valve 3. To prevent evaporation and toobtain the right taste, serving temperature and appearance, a smallamount of cold water must be added to the hot water along the pipe 4into the pipe 1 by controlling the amount by means of the valve 6 and byopening the valve 5, when the hot water is taken from the steamgenerating, pressurized hot-water tank. The hot-water storage tank canalso be open and operate in normal pressure.

According to a preferred embodiment, the dwell time of the concentratein the storage vessel is from 2 min to 6 h, preferably from 10 min to 30min. The temperature in the vessel is preferably selected so that thetemperature of the coffee concentrate will not change more than 2° C.during one hour. Both the storage vessel and the mixing tank work innormal pressure.

According to another preferred embodiment, the invention can also beimplemented so that hot water is taken from an open hot-water tank thatoperates in normal pressure. In that case, hot water at a correcttemperature can also be added to the concentrate along the pipe 1 byopening the valve 2, in an amount controlled by the valve 3; adding coldwater is not necessary.

Water and the coffee concentrate blend, when the streams of coffee andwater are combined. By virtue of the flow, homogenisation takes place inthe mixing tank 7, and further in the serving dish 15. In the solutionaccording to the invention, the mixing tank 7 can also be provided witha separate mixer.

According to an embodiment of the invention, the heat vessel 11 isprovided with sensing elements 14, through which the coffee maker'sprogram gives the cooker a command to prepare a concentrate.

In conclusion, the coffee concentrate prepared according to theinvention is transferred 12 directly to the hermetically sealed heatvessel 11, from where it is measured into the final drink in portionssuitable for the respective use. The coffee concentrate is hermeticallystored in the vessel 11 and transferred to the mixing tank 7immediately, preferably less than 5 minutes before serving. The desiredamounts of hot and cold water are also transferred to the mixing tankalong the pipes 1 and 4. The amount of water and that of the coffeeconcentrate are controlled by the valves.

According to a preferred embodiment of the invention, the hot milkand/or milky foam needed in the preparation of specialty coffees, suchas cappuccino and café au lait, can be measured into the drink in theserving dish 15 from a separate milk container (not shown) by means ofthe steam heated by the milk foaming device simultaneously, but in aspecific order, with the coffee.

Water can be added when making specialty coffees and also when preparingcoffee drinks. Using hot water at a correct temperature, “ordinary”coffee with a desired strength, i.e., coffee that corresponds tofiltered coffee is made from the coffee concentrate.

Water can also be used as addition when making tea drinks. In this way,a tea drink with a desired strength is obtained. Milk can also be addedto the tea in the same manner as in the example of the specialty coffeedescribed above.

The coffee concentrate can also be used as such for making coffee drinksand specialty coffees. In that case, no water is added into the mixingtank, and the coffee concentrate is measured into the serving dish assuch without dilution.

1-13. (canceled)
 14. A method for preparing coffee-based drinks,according to which method a coffee concentrate is extracted from acoffee powder by means of the espresso method wherein an apparatuscontaining a cooker portion for making coffee by the espresso method,and a hermetic storage vessel connected to the cooker portion, whichvessel is isolated and heatable, and operating at normal pressure isused, the concentrate made by the espresso method is transferred intothe storage vessel wherein the concentrate is preserved for a specificdwell time at a temperature that is selected in advance, and theconcentrate is transferred into a mixing tank that operates in normalpressure, to which mixing tank water is optionally measured so as tomake a coffee drink of a desired strength, after which the finisheddrink is poured into a serving dish.
 15. A method according to claim 14,wherein the temperature of the hermetic storage vessel is in a range of85-92° C., preferably 90 to 92° C.
 16. A method according to claim 14,wherein the dwell time of the concentrate in the storage vessel is from2 minutes to 6 hours, preferably from 10 minutes to 30 minutes.
 17. Amethod according to claim 14, wherein the coffee concentrate istransferred into the mixing tank immediately before serving, preferablyless than 5 minutes before serving.
 18. A method according to claim 14,wherein 7 to 15 grams, preferably 8 to 12 grams of coffee/55 cm³ ofwater is used for making the coffee concentrate.
 19. A method accordingto claim 14, wherein hot and/or cold water are/is added into the mixingtank.
 20. A method according to claim 14, wherein the amount of coffeeconcentrate and both cold and hot water, which enter the mixing tank, iscontrolled by the valves that are in the pipelines.
 21. A methodaccording to claim 14, characterized in that hot water is added from astream-generating pressure tank.
 22. An apparatus for makingcoffee-based drinks, the apparatus containing a cooker portion that isused to make coffee by the espresso method, and a storage vessel,wherein the storage vessel of the coffee concentrate, which is connectedto the cooker portion and which is hermetic, heated and preserves thetemperature of the concentrate, and a mixing tank, which is connected tothe storage vessel and which has pipeline fittings for cold and hotwater and a pipe fitting for taking the finished coffee drink out of theequipment, whereby the mixing tank makes it possible to mix the coffeeconcentrate and water in a suitable proportion so as to obtain a coffeedrink with a desired strength, whereby the storage vessel and the mixingtank are adapted to operate in normal pressure.
 23. An apparatusaccording to claim 22, wherein the temperature in the hermetic storagevessel can be adjusted to between 85 and 92° C., preferably 88 to 92° C.24. An apparatus according to claim 22, wherein hot and/or cold watercan be added into the mixing tank.
 25. An apparatus according to claim22, wherein the amount of the coffee concentrate, the cold and hot waterentering the mixing tank can be controlled by means of the valves in thepipelines.
 26. An apparatus according to claim 22, wherein thearrangement is used for making tea and tea drinks.